263results about "Polyphase network asymmetry reduction" patented technology

The invention relates to the technical field of power generation, power transformation or power distribution, and discloses a control method for preventing overload of an energy storage system transformer, which comprises the following steps: monitoring the three-phase total power and the power of each phase of a power grid side ammeter in real time, and calculating the three-phase unbalance degree based on the three-phase total power when the three-phase unbalance phenomenon occurs; when the three-phase unbalance degree is greater than a preset unbalance degree threshold value, dynamically adjusting the charging power of the energy storage converter according to a starting threshold value, a charging limiting threshold value and a charging forbidding threshold value by adopting a multi-threshold value dynamic adjustment mechanism; the phase with the maximum deviation between the power of each phase and the average power of the three phases is calculated as an overload phase, load reduction is performed on the overload phase based on a load increasing and decreasing strategy, load increasing is performed on a non-overload phase, and the adjusted three-phase power is obtained; a power distribution instruction is calculated in real time in combination with a dynamic response mechanism, and the three-phase unbalance degree does not exceed a safety threshold value in cooperation with total power control. The problems of easy overload, three-phase imbalance and slow response of a transformer in the prior art are solved, and the purposes of accurate load control, high system stability and high response speed are achieved.

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.

The invention discloses a three-phase imbalance compensation method and system based on negative sequence current and a medium, and relates to the technical field related to power imbalance compensation, and the method comprises the steps: executing the three-phase current, voltage and reactive power data collection of a power distribution network, and carrying out the three-phase imbalance recognition through negative sequence current analysis; carrying out additional acquisition of a load mode and environment data on the power distribution network; taking the data acquisition result and the additional data set as input data to execute negative-sequence current change trend prediction; a double-layer compensation device is configured for cooperative control optimization; power distribution network balance compensation is executed through a time sequence compensation strategy, and time sequence window feedback is established; and carrying out adaptive strategy correction. The technical problems that in the prior art, a three-phase imbalance compensation strategy lacks perspectiveness and self-adaptive capacity and cannot cope with a dynamically-changing power grid scene, and consequently compensation precision and stability are poor are solved, and the technical effects that perspectiveness and predictive compensation is achieved, and three-phase imbalance compensation precision and stability are improved are achieved.

The invention discloses an intelligent commutation type three-phase imbalance dynamic treatment method for a power distribution network, relates to the technical field of power distribution network treatment, and aims to solve the problem of poor treatment effect of three-phase imbalance. By using the data mining and analysis technology, not only can the cost minimization path be calculated according to the current state, but also the future change can be pre-judged in combination with the load dynamic trend, so that the formulated switching strategy is more prospective and accurate, the generated high-dimensional mapping vector fuses the node characteristics and the neighbor node characteristics, and the switching efficiency is improved. By combining the use of a nonlinear activation function, the model can adaptively learn a load change rule, sensor equipment integrates various sensors and chips, has the functions of environment monitoring, power management and the like, and is matched with structural components to ensure the reliable operation of the device, reduce the operation and maintenance cost and difficulty and prolong the service life of the equipment.

The invention belongs to the technical field of electric energy quality control, and provides an energy storage type medium-voltage voltage sag and interruption treatment device and a control method thereof.The energy storage type medium-voltage voltage sag and interruption treatment device is arranged between a large power grid and a load in series and comprises a series converter PCS1, a parallel converter PCS2, an energy storage module, an injection type series transformer T1, a parallel transformer T2, a bypass static switch STS and a bypass relay KM1; wherein the injection type series transformer T1 is connected with a large power grid, and the parallel transformer T2 is connected with a load; the series converter PCS1 is connected with the injection type series transformer T1 through the bypass static switch STS and the bypass relay KM1, and compensation voltage is generated in real time through the injection type series transformer T1; the parallel converter PCS2 is respectively connected with the parallel transformer T2 and the common direct current busbar; and the energy storage module is arranged on the common direct current busbar between the series converter PCS1 and the parallel converter PCS2 in parallel.

The invention belongs to the technical field of power grid control, and relates to a transformer area flexible interconnection system three-phase imbalance control method and device and a medium. Taking the transformer area converter controlled by the PQ control algorithm as a target transformer area converter; collecting a first control parameter output by an active power PI controller of the target transformer area converter; based on the upper and lower limits of the voltage target value of the DC bus, performing amplitude limiting setting on the first control parameter of the target transformer area converter to obtain the voltage target value; subtracting the voltage target value from the actual voltage value of the direct-current bus, inputting the difference value into the PI controller, and outputting a second control parameter of the target transformer area converter; taking the second control parameter as a direct-axis current target value, subtracting the direct-axis current target value from a direct-axis current actual value, and taking the difference value as the input of a direct-axis current PI controller; and controlling the target transformer area converter based on the voltage modulation signal output by the PQ control framework. The scheme can effectively improve the power supply reliability of the power distribution area and stabilize the DC bus voltage.

Disclosed in the present invention are an operation and maintenance method and apparatus for severe overload and three-phase imbalance of a distribution transformer, and a medium. The method comprises: by quantifying the degree of difference between devices as the distance between two points, performing clustering analysis on an operation and maintenance state of a distribution transformer, so as to obtain a classification result; and on the basis of a short-term single-phase severe overload category and a short-term three-phase severe overload category in the classification result, establishing a multi-objective optimization model and solving same, so as to obtain a multi-objective optimization result, and on this basis, formulating a day-ahead source-load distribution transformer operation and maintenance plan and performing operation and maintenance control on a distribution network. The present invention provides an operation and maintenance method and apparatus for severe overload and three-phase imbalance of a distribution transformer, and a medium. Solving a multi-objective optimization model to obtain a multi-objective optimization result can ensure that operational risks caused by three-phase imbalance are reduced while balancing three-phase loads, such that differentiated operation and maintenance can be achieved by means of a day-ahead source-load distribution transformer operation and maintenance plan, thereby solving the problem of difficulty in managing severe overload and three-phase imbalance of a distribution transformer to formulate a targeted operation and maintenance plan.

Disclosed embodiments provide methods, systems, and computer program products for implementing enhanced phase power load balancing of a set of systems (e.g., the set of systems of a data center) using a subset of the systems. Disclosed embodiments extract phase currents of a three-phase power source of the set of systems, and determine, based on extracted phase currents for the set of systems, input phase power load balancing for the subset of the systems. Disclosed embodiments alter the current input phase power balancing of the subset, unbalancing the input phase power load for the subset of the systems to provide enhanced phase power load balancing of the set of systems. Altering the current input phase power balancing for the subset of the systems can be implemented by power shifting between power supply units (PSUs), phase rotations, or input phase switching of power distribution unit (PDU) switchable output ports.

The invention discloses a method and a system for regulating and controlling imbalance of a power distribution area, which are used for solving the technical problem of poor operation stability of the power distribution area caused by a traditional method for regulating and controlling imbalance of the power distribution area. The method comprises the following steps: acquiring three-phase bus voltage and three-phase current of a power distribution area; generating a power distribution area three-phase component voltage and a power distribution area power optimization objective function according to the power distribution area three-phase bus voltage and the power distribution area three-phase current; solving the power optimization objective function of the power distribution area, and outputting predicted power of the power distribution area; calculating a three-phase reference current of the power distribution area based on the predicted power of the power distribution area and the three-phase component voltage of the power distribution area; and according to the three-phase reference current of the power distribution area, generating a power distribution area imbalance regulation and control signal.

The invention relates to a power system voltage control technology, in particular to a method and equipment for maintaining grid-connected point voltage three-phase balance under weak power grid unbalanced disturbance, and the method comprises the following steps: firstly, establishing a small signal model of a converter grid-connected system after unbalanced disturbance, and emphatically considering the phasing error influence of a phase-locked loop transient process; then, the fluctuation quantity of the amplitude and phase of the PCC voltage induced by unbalanced disturbance is accurately calculated, the influence is counteracted through a power outer ring feed-forward compensation mode, and three-phase balance of the PCC voltage in the transient state and the steady state process is achieved under the condition that the weak power grid unbalanced disturbance is maintained. According to the method, the influence of the machine-network interaction of the weak power grid on the dynamic characteristics of the PCC voltage is considered, and a better voltage balance maintaining effect is achieved in the weak power grid. Through composite control, according to PCC voltage vector amplitude and phase disturbance compensation, system transient state and steady state whole-process voltage balance maintenance after unbalanced disturbance is realized. The control structure is simple, and the robustness of the system is improved.

The invention discloses a transformer parallel operation circulating current suppression method and system based on a cloud edge collaborative architecture, and relates to the technical field of power grid control, and the method comprises the steps: an edge node collects the multi-source dynamic data of a parallel transformer in real time, and constructs a local dynamic impedance model of a single transformer; the cloud receives the multi-modal data uploaded by each edge node, inputs the multi-modal data into an LSTM-SVM hybrid model trained based on a historical database, generates an impedance prediction weight of each edge node, and issues the impedance prediction weight to the corresponding edge node; the edge node receives the impedance prediction weight and injects the impedance prediction weight into a local dynamic impedance model to generate a corrected dynamic impedance matrix; and calculating a circulating current suppression instruction according to the corrected dynamic impedance matrix, and executing real-time regulation and control based on the circulating current suppression instruction. According to the method, the impedance prediction weight is generated through real-time collection of the edge nodes and calculation of the cloud, the local dynamic impedance model is effectively corrected, and then the circulating current suppression instruction is accurately calculated.

The invention relates to the technical field of intelligent operation of a power distribution network, in particular to an intelligent three-phase imbalance treatment method, which comprises the following steps of: firstly, acquiring three-phase current, three-phase voltage and electrical characteristic quantity of each single-phase load, and carrying out commutation adaptability evaluation on the load based on a real-time power factor, a current harmonic distortion rate and a load power flow direction; and calculating the three-phase unbalance degree of each power supply branch, identifying an extreme branch with the unbalance degree exceeding the standard, and screening out loads with optimal commutation adaptability parameters to form a candidate load set. And generating a commutation priority sequence for the candidate load through a historical commutation frequency and real-time contribution degree two-factor model. And triggering zero-millisecond seamless commutation under the conditions of meeting a safe voltage threshold and equal voltage time, verifying a switching result after commutation, limiting the number of commutation times of single treatment, and monitoring the three-phase unbalance degree in real time until the three-phase unbalance degree is recovered to a qualified range. According to the invention, the accuracy and safety of the commutation decision can be improved, and the dynamic balance adjustment of the three-phase load is realized.

The invention provides an electric energy quality control method and system based on an energy storage system, relates to the technical field of electric energy quality control, and aims to identify collaborative disturbance attributes during voltage sag and three-phase imbalance through dynamic distortion information, perform scheduling amplitude limiting compensation on the collaborative disturbance attributes, and improve the control accuracy of the electric energy quality. Obtaining a layered amplitude limiting inflection point when the electric energy in the energy storage system is intelligently scheduled in the load-storage balance constraint region; carrying out fusion correction on the circulation out-of-limit deviation, generating a dynamic peak regulation criterion when the power grid carries out energy storage transfer adjustment in multiple time scales, and further determining a regulation and control guidance strategy during electric energy balance regulation and control in the energy storage system according to the dynamic peak regulation criterion; and performing tolerance adaptation control on the power quality of the power distribution network in the composite disturbance scene according to the hierarchical amplitude limiting inflection point and the regulation and control guidance strategy. According to the invention, tolerance adaptation control can be carried out on the power quality of the power distribution network in a composite disturbance scene, so that the power quality management and control efficiency under the participation of an energy storage system is improved.

The invention discloses an unbalance compensation method and system for an energy storage converter, and belongs to the field of power electronics and electric energy quality treatment. The system comprises a power instruction analysis module, a current reference generation module, a negative sequence current control loop module, a zero sequence control loop module, a positive sequence control loop module, a pulse width modulation module, a first conversion module and a second conversion module, the current reference generation module is respectively connected with the negative sequence current control loop module and the positive sequence control loop module; the third end and the fourth end of the negative sequence current control loop module are connected with the pulse width modulation module through the second conversion module; the third end and the fourth end of the zero sequence control loop module and the third end and the fourth end of the positive sequence control loop module are connected with the pulse width modulation module through the first conversion module. According to the method, the energy storage and compensation functions of the PCS can be seamlessly integrated under a unified control framework, so that the control system is greatly simplified, and the performance is remarkably improved.

The invention provides a dynamic three-phase imbalance treatment system and method with an intelligent phase-change switch, and relates to the technical field of power system distribution network operation control. The system comprises a load monitoring unit, a central control unit and an intelligent phase-change switch array. According to the treatment method, the load monitoring unit collects load current and voltage data of each phase in real time and transmits the data to the central control unit; the central control unit adopts a load balance decision model based on an improved particle swarm algorithm to analyze and process the acquired data so as to calculate an optimal commutation scheme; and the intelligent phase-change switch array completes load phase sequence switching within millisecond-level time through a solid-state phase-change switch with rapid on-off capability according to the control instruction, so that three-phase load dynamic balance adjustment is realized. By adopting the scheme of the invention, the real-time performance and the adjustment precision of three-phase imbalance treatment can be obviously improved, the method adapts to complex and changeable distribution network load working conditions, the line loss is effectively reduced, and the utilization rate of the transformer and the operation stability of the distribution network are improved.

The invention relates to a method for identifying asymmetrical vibrations during the operation of an electric device (1) which is connected to a high-voltage grid, wherein - vibrations of the electric device (1) are detected using vibration sensors (8) which provide measured values on the output side, - the measured values and / or values derived from the measured values are transmitted to a communication unit (12) via a close-range communication connection (11), - the measured values and / or the values derived from the measured values are transmitted by the communication unit (12) to a data processing cloud (9) via a far-range communication connection (13), - the measured values and / or the values derived from the measured values are separated into frequency components by the data processing cloud (9) using a Fourier transformation, thereby obtaining a frequency spectrum, - odd and even frequency components of the frequency spectrum are ascertained on the basis of a base frequency of the high-voltage supply grid and put into a ratio R relative to one another, and - the presence of asymmetrical vibrations is indicated if the ratio R exceeds a specified threshold.

The application discloses a kind of three-phase load imbalance monitoring alarm method.The method comprises: obtaining the current data, power data and appeal work order data of target area at multiple sampling time points;According to the current data and power data, determine the three-phase load imbalance type of target area;According to three-phase load imbalance type and appeal work order data, determine whether to send risk alarm to target area.The technical scheme provided by the embodiment of the application obtains the current data and power data of multiple sampling time points in the target area, thereby obtaining the working condition of the distribution transformer in the target area at multiple sampling time points, and then determining the three-phase load imbalance type of the target area.Combined with the appeal work order data fed back by the actual experience of users in the target area, the power supply condition in the target area can be judged more accurately, and the target area needing to send risk alarm is prompted, so that the technical effect of improving the management efficiency of power grid and the satisfaction of users is realized.

The application discloses a phase sequence identification method and device, a storage medium and electronic equipment. The method comprises the following steps: collecting voltage time sequence data samples of a total table and each single-phase table to construct initial sample data sets corresponding to each phase sequence and containing a plurality of voltage time sequence data samples; performing calculation and processing based on each initial sample data set to obtain initial clustering center data sets corresponding to each initial sample data set, so as to obtain an initial phase sequence identification model; cyclically updating the initial phase sequence identification model based on each to-be-identified sample, and obtaining a phase sequence identification model when a preset iteration condition is met; identifying a target to-be-identified sample based on the phase sequence identification model, determining a target clustering center corresponding to the target to-be-identified sample, and determining a phase sequence corresponding to the target clustering center as a target phase sequence corresponding to the target to-be-identified sample. The phase sequence identification method in the application does not require manual identification of the phase sequence on site, saves manual cost, and improves work efficiency.

The invention discloses a liquid inlet balance control method for multiple parallel three-phase separators, which comprises the following steps: taking the water yield of the three-phase separators as a basic parameter of a flow regulating valve of a liquid inlet pipeline, when the water yield of a certain three-phase separator exceeds a certain range of an average value, calculating a ratio Px of a water yield difference value Xi to the current water yield Xi by a control system, and the opening degree of the flow regulating valve is regulated according to Px, so that rapid balance control over the liquid inlet amount of the multiple three-phase separators is achieved. According to the liquid inlet balance control method for the multiple parallel three-phase separators, the problem that the liquid inlet balance control effect of the three-phase separators is poor due to the fact that the gas content of crude oil is large and the liquid inlet amount is not measured accurately is solved, and the situation that crude oil treatment does not reach the standard due to the fact that the liquid inlet amount of a certain three-phase separator is too large due to bias flow is avoided.

The invention relates to the technical field of power systems, in particular to a monitoring method and equipment for a three-phase load unbalance adjusting device and a medium, and the method comprises the steps: carrying out the precise prediction of the three-phase active power, power factors and unbalance degree of a plurality of time nodes in the future based on a historical monitoring data set; therefore, the system can identify an imminent risk time period in advance; on the basis of the prediction result, a generated target supplement instruction can be issued in advance and adjusted before unbalance actually occurs; adjustment lag is avoided, the load switching or compensation process can be completed in advance in the period when the load is relatively smooth, smooth adjustment without perception of a user is achieved, the problem that equipment frequently acts near a critical point due to passive response is effectively solved, and therefore the service life of execution devices such as a phase-change switch and a contactor is greatly prolonged.

The invention relates to the technical field of rural power distribution networks, and provides an agricultural power distribution network three-phase imbalance energy storage and power mutual aid allocation system, which comprises a monitoring unit, a power distribution unit, a power distribution unit and a power distribution unit, a decision unit: when delta Ugt; when 5%, triggering adjustment, and identifying the highest voltage phase, the lowest voltage phase and the intermediate voltage phase; the execution unit comprises a power mutual aid module and an energy storage adjusting module; and the power mutual aid module is used for transferring the excess power of the phase with the highest voltage to the phase with the lowest voltage through the three-phase converter. The three-phase voltage deviation ratio is reduced to be within 3%, the intermediate phase voltage is stabilized to be + / -2%, and THDlt is achieved through harmonic suppression; and the voltage of the direct-current bus is stabilized at 750-800V, so that the power supply quality and economical efficiency of the agricultural distribution network are improved.

The invention provides a double-circuit power supply balancing device and a balancing control method, and relates to the technical field of data center power supply, and the double-circuit power supply balancing device comprises two power distribution units which are respectively connected with two independent power supply modules of IT equipment; each power distribution unit comprises a three-phase circuit, each phase circuit is connected in parallel to an external power supply and comprises an upper bridge arm and a lower bridge arm, and the midpoint of the upper bridge arm and the midpoint of the lower bridge arm are connected with a power supply module; each of the upper bridge arm and the lower bridge arm comprises a plurality of submodules which are sequentially connected in series; the balance control module is connected with the power distribution unit and is used for realizing total energy balance of the power distribution unit, bridge arm balance current and energy balance between bridge arms. The system has the advantages that a three-level hierarchical control strategy is adopted for solving the problem of uneven energy in double-circuit power supply, overall energy balance, inter-phase energy balance and inter-bridge-arm energy balance are achieved by controlling total current, inter-phase direct-current circulation and inter-bridge-arm fundamental-frequency circulation respectively, direct-current side interference can be avoided through decoupling control, the challenge of uneven energy distribution is systematically solved, and the system is suitable for large-scale popularization and application. And power supply stability and electric energy quality are ensured.

This invention discloses a method for improving the transient characteristics of wind turbines based on wind-storage integration. Aiming to improve the grid adaptability and power quality of wind turbines, this invention adopts the following scheme: when the grid connection point voltage of the wind turbine is detected to be in a low-voltage ride-through state, the wind-storage integration system switches to low-voltage ride-through mode; when the grid connection point voltage of the wind turbine is detected to be in a high-voltage ride-through state, the wind-storage integration system switches to high-voltage ride-through mode; when there is no trigger signal, the wind-storage integration system is in power quality mode. The advantage is that it integrates the fault ride-through control algorithms and power quality control algorithms of energy storage and wind turbines based on the wind-storage integration hardware topology, achieving unified coordination of the wind-storage integration control system and improving the transient characteristics of the wind turbine.

The invention relates to a power prediction control method of a doubly-fed motor converter under a three-phase imbalance condition. The power prediction control method comprises the following steps: step 1, constructing a power prediction model of a three-phase voltage source converter under a three-phase power grid voltage imbalance state; 2, predicting a six-power component change value of the three-phase voltage source converter in the next control period based on the power prediction model; step 3, setting a value function and calculating the action duration of the voltage vector in the next control period by minimizing the function; and 4, realizing power switch control of the three-phase voltage source converter by adopting a space vector pulse width modulation technology. The method has the advantages that the active power, the reactive power and the harmonic components of the three-phase voltage source converter with the alternating-current-to-direct-current conversion function in the doubly-fed motor speed regulation system can be controlled under the condition that the three-phase power grid voltage is unbalanced, and the purpose of improving the efficiency and the control performance of the doubly-fed motor speed regulation system is achieved.

The application discloses a kind of three-phase balanced power supply energy-saving control method and system, method includes: building three-phase four-wire soft switching topological model, and real-time operating parameter of power supply system is collected and transmitted to complex domain convex optimization decision platform;Parameter characteristics are extracted in the platform, determine key parameters and establish its mapping relationship with three-phase unbalance degree, energy loss;Mapping relationship is input into multi-objective symmetric semi-positive programming algorithm, with three-phase unbalance degree and energy loss minimization as target to construct constraint condition, and the optimal conduction timing of controllable switching element, duty ratio and filter component optimal parameter are solved;Optimal parameter is fed back to topological model, and the working state of component is adjusted to realize control.System contains six units, and each unit works cooperatively.The application can reduce energy consumption, accurately control three-phase balance, adapt to complex working conditions, improve the operating efficiency and stability of power supply system, meet the dual needs of energy saving and balance of power system.

The invention belongs to but not limited to the technical field of aviation power supply system control, protection and fault monitoring, and particularly relates to a three-phase AC voltage imbalance detection and alarm circuit. Comprising a three-phase AC voltage sampling module used for collecting a three-phase AC input voltage and outputting a three-phase AC voltage effective value; the voltage difference detection module is used for detecting the difference value of any two-phase alternating-current voltage and outputting the absolute value of the difference value of the effective values of any two-phase alternating-current voltage; the hysteresis comparison module is used for judging whether the absolute value of the difference value of the effective values of the AC voltages of any two phases exceeds a three-phase voltage imbalance judgment threshold value or not, and outputting an imbalance state signal of any two phases; the logic judgment module is used for carrying out logic OR operation on any two-phase unbalanced state signals of the three phases and outputting three-phase voltage unbalanced state signals after fixed time delay; and the alarm output driving module is used for performing power amplification on the three-phase voltage imbalance state signal and then driving an external three-phase voltage imbalance fault indicating lamp.

The invention discloses an automatic compensation load balancing system and method for connecting distributed power supplies to a three-phase unbalanced power grid, and the system comprises a plurality of distributed power supplies and a load balancing control module, and each distributed power supply and load balancing control module is provided with a wireless ad hoc network communication module. All the distributed power supplies and the load balance control modules form a communication network through respective wireless ad hoc network communication modules; each wireless ad hoc network communication module is connected with the load balance control module through an edge calculation module, and in the edge calculation module, a double-buffering mechanism is adopted for data processing; the load balance control module comprises a load balance controller, a compensation current adjusting unit and a load distribution unit; through the application of the automatic compensation load balancing device, the problem of three-phase imbalance of the power grid is effectively solved, the situations that the power supply efficiency is reduced and the equipment loss is increased are reduced, and the economical efficiency and the reliability of power grid operation are improved.

The application discloses a method and system for off-grid sequence separation droop control of a converter adapted to unbalanced load, which comprises the following steps: performing positive sequence droop control on active power and reactive power under a positive sequence fundamental frequency to obtain a positive sequence voltage vector and a positive sequence fundamental angle; performing negative sequence droop control on active power and reactive power under a negative sequence fundamental frequency to obtain a negative sequence voltage vector and a negative sequence fundamental angle; obtaining a negative sequence voltage dq-axis component reference value according to the positive sequence fundamental angle and the negative sequence fundamental angle; simultaneously, taking the positive sequence voltage vector and 0 as a positive sequence voltage dq-axis component reference value; and obtaining a modulation voltage of a power unit of the converter according to the positive sequence voltage dq-axis component reference value and the negative sequence voltage dq-axis component reference value, the positive sequence dq-axis component and the negative sequence dq-axis component of the converter serving as feedback values, and voltage and current double-loop regulation control being based. The application realizes active power and reactive power sequence separation extraction control, improves load voltage unbalance degree, realizes load negative sequence current sharing, enhances system stability, and has stronger unbalanced load capacity.

The application provides a motor three-phase current imbalance compensation method and device, electronic equipment and a computer readable storage medium. The method comprises: calculating a target peak current corresponding to a three-phase current of a motor in real time; performing peak sampling on the three-phase current to obtain a corresponding actual peak current; determining a three-phase current imbalance based on the target peak current and the actual peak current; determining a compensation voltage based on the three-phase current imbalance; and compensating the three-phase current based on the compensation voltage. Through the application, real-time compensation of three-phase current imbalance can be achieved without adding additional devices.

The invention belongs to the field of network construction energy storage, and particularly relates to a peak current amplitude limiting method and system for a network construction type energy storage power grid. The method comprises the steps that according to a dq-axis current instruction output by a network construction control model, an abc-axis three-phase current instruction is obtained through conversion; obtaining a three-phase virtual beta-axis current instruction according to the abc-axis three-phase current instruction; according to the abc-axis three-phase current instruction and the three-phase virtual beta-axis current instruction, the amplitude of the three-phase current instruction is obtained; obtaining a peak current instruction according to the maximum value in the amplitudes of the three-phase current instruction; and when the peak current instruction is greater than a set amplitude limiting value, dividing the current instruction of the network construction control model by the peak current instruction to obtain a current instruction after amplitude limiting so as to perform network construction control. The method can ensure that the peak current can be accurately limited within the set amplitude limiting value during the grid construction energy storage low-voltage ride-through period, is not influenced by a three-phase current imbalance strategy, is high in applicability, does not need to wait for at least one current period, and is higher in amplitude limiting speed.